EPA has issued a cancellation order for registered products using sulfoxaflor, in response to a Sept. 10 decision by the federal Ninth Circuit Court of Appeals that found the agency violated federal law when it approved the pesticide's registration without additional studies regarding potential impact on honeybees.

The cancellation order means distribution or sale of sulfoxaflor products are prohibited, unless such sales are for disposal or export. However, EPA noted that use of existing stocks by end-users is permitted provided such use is consistent with the product's approved labeling.

EPA also said maximum pesticide residue levels for sulfoxaflor are not affected by either the court's decision or the agency's cancellation order, so crops that have been properly treated with sulfoxaflor or that may be treated with existing stocks as described in the final cancellation order can still be sold legally.

The appeals court order vacated EPA's unconditional registration in 2013 of two products invented by Dow AgroSciences LLC with the active ingredient sulfoxaflor, at the time a new insecticide that targets a range of pests. EPA initially proposed to conditionally register sulfoxaflor and requested additional studies to address data gaps regarding the pesticide's effects on bees.

"A few months later, however, the EPA unconditionally registered the insecticides with certain mitigation measures and a lowering of the maximum application rate. It did so without obtaining any further studies," according to Judge Mary Schroeder, who wrote the court's opinion.

The three-judge panel concluded that the "unconditional approval was not supported by substantial evidence."The court ordered EPA to obtain further studies of the effects of sulfoxaflor on bees.

In response to the cancellation order, DowAgroSciences issued the following statement.

"As a result of the extensive data currently available on sulfoxaflor, Dow AgroSciences expects the pollinator protection concerns expressed in (the court) decision to be readily and thoroughly addressed by EPA through further review of scientific data, supporting pressing grower needs for protection against destructive crop pests with renewed U.S. registrations of sulfoxaflor-containing products.

"Four full years of widespread U.S. product use - with additional use in Canada, Australia and other nations - have demonstrated excellent sulfoxaflor performance worldwide with no noted adverse effects on pollinators.

"Dow AgroSciences remains confident in the benefits offered by this new class of insecticides and will work diligently with EPA and states to achieve new registrations for these important products to support the American grower."

The company also said that "contrary to misrepresentations circulated by pesticide opponents, sulfoxaflor is a sulfoximine-class insecticide, not a neonicotinoid, a distinction clearly established by the Insecticide Resistance Action Committee (IRAC) and published in the open scientific literature."